North Frisian is a language that is spoken on the German North Sea coast near the Danish border. It has about 10,000 speakers, in which the dialects of the mainland and those of the islands (Sylt, Föhr, Amrum, and the rocky island Helgoland) show mutual differences.

The language might have been brought there by two successive migration waves from the south coastal regions of the North Sea, in the 8th century to the islands and in the 12th century to the mainland. Some similarities can be noticed with West Frisian (Frysk), which is spoken in the Dutch province of Frisia by at least 350,000 people, as well as with Sater Frisian (Seeltersk) in the Saterland community, Lower Saxony, Germany, spoken by about 2,000 people.